THE CLEAVAGE PLANE IN SEMICLOSED ENDARTERECTOMY OF THE SUPERFICIAL FEMORAL-ARTERY - A HISTOLOGIC-STUDY

Purpose: The purpose of this study was to determine the cleavage plane in semiclosed endarterectomy of the superficial femoral artery, a his tologic study of endarterectomy cores of 10 consecutive patients was p erformed. Superficial femoral artery occlusive disease consisted of mu ltiple stenoses in one and an occlusion in the other cases. Methods: M icroscopic paraffin cross-sections were made every half centimeter of the endarterectomy core. The sections were stained with hematoxylin-eo sin and with elastica van Gieson. Microscopic studies were conducted o f a total of 484 sections. Intima, internal elastic membrane, media, e xternal elastic membrane, and adventitia were identified, if present. Results: When the procedure of separating the diseased intima from the remainder of the arterial wall was commenced, the cleavage plane was located between the internal elastic membrane and the media in most ca ses. In two cases the cleavage plane was located inside the intima, an d in one case parts of the media were removed as well. During passage of the ring stripper through the artery, the location of the cleavage plane changes and extends into the media. In one patient a residual st enosis was located in the segment of the core in which only the intima and internal elastic membrane were removed. In two patients the endar terectomy core contained parts of the external plastic membrane as wel l. During passage of the ring stripper through the artery, the locatio n of the cleavage plane changes. In some segments the media is left in tact, whereas in other segments the media is partially or totally remo ved. The reason for the variability of the cleavage plane rests in the nature of the pathologic behavior of the atheroma. The tissue necrosi s that is part of the atheromatous complex frequently dips beyond the internal elastic membrane into the media and even into the external el astic membrane and adventitia. Conclusions: The question remains as to whether the location of the cleavage plane has an influence on the lo ng-term results of endarterectomy. Long-term follow-up studies are req uired to supply us with the answer.